Car Battery Charger


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This charger will quickly and easily charge most any lead acid battery. The charger delivers full current until the current drawn by the battery falls to 150 mA. At this time, a lower voltage is applied to finish off and keep from over charging. When the battery is fully charged, the circuit switches off and lights a LED, telling you that the cycle has finished.

Schematic

This is the schematic of the Car Battery Charger

Parts

Part
Total Qty.
Description
Substitutions
R11500 Ohm 1/4 W Resistor
R213K 1/4 W Resistor
R311K 1/4 W Resistor
R4115 Ohm 1/4 W Resistor
R51230 Ohm 1/4 W Resistor
R6115K 1/4 W Resistor
R710.2 Ohm 10 W Resistor
C110.1uF 25V Ceramic Capacitor
C211uF 25V Electrolytic Capacitor
C311000pF 25V Ceramic Capacitor
D111N457 Diode
Q112N2905 PNP Transistor
U11LM350 Regulator
U21LM301A Op Amp
S11Normally Open Push Button Switch
MISC1Wire, Board, Heatsink For U1, Case, Binding Posts or Alligator Clips For Output

Notes

  1. The circuit was meant to be powered by a power supply, which is why there is no transformer, rectifier, or filter capacitors on the schematic. There is no reason why you cannot add these.
  2. A heatsink will be needed for U1.
  3. To use the circuit, hook it up to a power supply/plug it in. Then, connect the battery to be charged to the output terminals. All you have to do now is push S1 (the "Start" switch), and wait for the circuit to finish.
  4. If you want to use the charger without having to provide an external power supply, use the following circuit.

    This is the schematic of the Car Battery Charger Power Supply

    Part
    Total Qty.
    Description
    Substitutions
    C116800uF 25V Electrolytic Capcitor
    T113A 15V Transformer
    BR115A 50V Bridge Rectifier10A 50V Bridge Rectifier
    S115A SPST Switch
    F114A 250V Fuse

  5. The first time you use the circuit, you should check up on it every once and a while to make sure that it is working properly and the battery is not being over charged.

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Comments

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anonymous
Car Battery Charger
Sunday, April 12, 2015 11:03:44 AM
I am a novice but I built this charger and it works just like it's supposed to. I am going to hook this up to a table fan that I converted to a generator and charge the battery on windy days. Great site.
richard
Car Battery Charger
Friday, October 21, 2011 8:11:48 AM
from the power supply the positive and negative of the supply connects to where in the charger? it only has one "IN" where does the negative of the supply go? the ground goes to the transformer right?
leochbattery
Car Battery Charger
Friday, September 16, 2011 5:10:16 AM
I just know more about car battery. Don't over charge the battery or it will damage it.
anonymous
Car Battery Charger
Thursday, September 01, 2011 6:59:10 AM
Can i use a 8amp 13.8V voltage regulator as an input supply for the car battery charger?
Lee
Car Battery Charger
Wednesday, February 09, 2011 3:17:59 PM
what should the output voltage of the charger be? i got around 15 V according to multisim. thanks
anonymous
Car Battery Charger
Thursday, October 28, 2010 8:41:28 AM
hi, when saying "most any lead acid battery" do you mean it will charge a 6 Volter too?
shoaib
Car Battery Charger
Sunday, October 10, 2010 7:04:10 AM
can i use any other diode instead of D1 IN457?help me plz....
Max
Car Battery Charger
Friday, June 25, 2010 1:15:25 PM
Thats a great circuit ! I am gonna use it as a storage battery charger. Thank You
siamak
Car Battery Charger
Sunday, June 20, 2010 11:41:25 PM
the circuit that u suggested has 18v input i think it should be DC voltage and as you know a 12v AC transformer after passing throgh a diode bridge give 18v DC( 12x2 root squire). so i think a 12vAC transformer with 3 amp current are enough for this circuit, is it ok?
Spooge
Car Battery Charger
Friday, May 28, 2010 8:38:17 AM
Nice circuit. what needs to be changed if i want to make it charge a 140 amp battery quckly. I need a 10A to 20Amps charger at least, For my ups, we get 4-5hrs blackout here every day.
fabieville
Car Battery Charger
Tuesday, March 16, 2010 7:57:01 AM
how do you wire several LM350's in parallel to use with this circuit? I tried wire 3 in parallel but it didn't work. So can u either show me a circuit with several wired that can use in this circuit or just explain as to how to do it please.
mojtaba
Car Battery Charger
Wednesday, March 10, 2010 2:45:25 PM
can you Substitute R1 500ohm with a 510? and R5 230 with a 220 i am unable to find them. thank you
gajah_gendut
Car Battery Charger
Wednesday, February 03, 2010 10:22:10 PM
for higher current about 5A, you can replace U1 with LM138/LM338
georgi
Car Battery Charger
Wednesday, January 20, 2010 2:24:24 PM
R1 1/4W ??? Out 3A R7 10W ???
baraa
Car Battery Charger
Friday, January 08, 2010 6:47:26 AM
what is the current output rating of this charger? cuz all of these equipment have current rating of milli amps i am an electrical engineering student but i haven't dealth with car batteries much, are all of them 12V (i mean to ask about the output voltage rating) thx a lot
brockster
Car Battery Charger
Monday, December 07, 2009 11:17:37 PM
@Woody: Oops, my error. The LM350 limits the maximum charge rate to 3 amps, not 2 amps. Running at 3 amps, you will need to heat sink the LM350 fairly well, even if the input voltage is only 18 volts or so.
brockster
Car Battery Charger
Monday, December 07, 2009 11:04:58 PM
Thanks for posting this useful circuit! @Randy: Yes, you can substitute 510 ohms for the 500 ohm resistor. Better yet, just use a diode, such as a 1N4006. The cathode side should point toward the "in" terminal in the schematic. @zizo: Yes, you can substitute any similar "small signal" type diode as long as it can handle 200 ma of current and 70 volts of repetitive reverse voltage. The popular 1N4148 ought to work. @anonymous: Use the momentary switch as indicated. This is just a "force to start the charge cycle" button. The cricuit may start charging even without pressing this button. You can find momentary switches at Radio Shack or any electronics parts shop. @Woody: The maximum charge rate is limited to 2 amps. This is set internally by the LM350 voltage regulator. @Martins and Umar: To get more output current you would need to add a "current pass" transistor to the circuit or use several LM350's in parallel. You would be better off not using this circuit and simply using another circuit rated at 10A. See the application circuits in the LM350 datasheet (link below) for ideas. @All: This circuit is from the LM350 datasheet. See this circuit, and other charger ideas, in the datasheet at http://cache.national.com/ds/LM/LM350.pdf
Tim
Car Battery Charger
Sunday, December 06, 2009 4:41:52 PM
I'm a mechanical engineering student working on a senior design project. All the electrical stuff is a little out of my element. I'm needing a circuit to charge a 12v car battery from a DC generator. Would this circuit be what i'm looking for?
Randy
Car Battery Charger
Friday, November 06, 2009 6:20:15 PM
can you Substitute R1 500ohm with a 510? and R5 230 with a 220 i am unable to find them. thank you
anonymous
Car Battery Charger
Saturday, September 12, 2009 9:54:40 AM
can i replace this switch with a non momentary switch
zizo
Car Battery Charger
Thursday, September 03, 2009 8:42:33 AM
I could'nt find D1 1N457 Diode. What can use else instead of it ??? is there any substitution ?? thank you.
woody
Car Battery Charger
Thursday, July 16, 2009 9:09:10 PM
I like your circuit but the info does not state the maximum current charge rate. please state same. thanks.
umar
Car Battery Charger
Saturday, July 11, 2009 3:12:11 AM
Thank's for your circuit. I need a battery charger that can charge 12 V 10 A. what can I do for that problem, can You send me circuit for that? Thank's....
anonymous
Car Battery Charger
Saturday, July 04, 2009 12:40:53 AM
Yes you can charge a 12v battery using another 12V battery. But connecting the two batteries directly will not charge the empty battery since the voltage difference is zero. You will need a DC to DC converter to convert 12vdc to a higer voltage level commoly 13.8vdc. You cannot expect that the empty battery will be fully charged before the the other battery is drained. You cannot transfer all the charge from the 1st battery to the 2nd since the DC to DC converter will dissipate some power (resistors, transistors, transformer....).
Arthur
Car Battery Charger
Wednesday, July 01, 2009 4:07:39 PM
I wanted to know if I can connect my car battery to the car battery charger while it is plugged up?
Sokvan In
24V-Car Battery Charger
Friday, June 26, 2009 6:36:06 AM
hello, i'm a student and i wanna ask you a question. i wanna make 24V-car battery charger. but i'm not sure how to make it. could you give me some advice, thanks beforehand.
Rob
Car Battery Charger
Wednesday, June 10, 2009 6:19:32 PM
I already built the circuit but when I first connected the battery the led turned off, but when a few minutes later I disconnected it and connected again and the light didn't turn off again...could you help me!!!
MARTINS
Car Battery Charger
Wednesday, May 27, 2009 1:59:06 AM
HOW CAN I IMPROVE THE OUTPUT CURRENT OF THE LM350 REGULATOR?
martins
Car Battery Charger
Wednesday, May 27, 2009 1:46:03 AM
how does lm301a 0p amp operates in the circuit diagram above?
TARIQ
Car Battery Charger
Monday, May 04, 2009 10:43:37 AM
Thanks for your circuit, It is very simple and easy to built, Can i charge a car battery 12V40Ah ?
Eric K
Battery charger/maintainer
Sunday, April 05, 2009 7:05:42 AM
I just bought a battery maintainer for $20 at a local shop and have seen similar items elsewhere for similar money. Google for "battery maintainer". I see Home Depot has a Black and Decker one listed for about that. Cheaper and a little less bulky than a full on battery charger.
OSCAR
Car Battery Charger
Saturday, April 04, 2009 6:42:14 PM
Thank you for the circuit
anonymous
Car Battery Charger
Thursday, March 19, 2009 12:40:56 PM
I need a battery charger that will allow me to charge up my battery, while drawing from it 12volts @ 6 amps intermittent. What unit do you recommend that will not allow ac to come into my two way radio? In other words, I want my battery to be topped off, while keeping the charger hooked up to it. Is this possible? Your suggestions/comments, etc. Thanks, Chuck
anonymous
Car Battery Charger
Wednesday, March 18, 2009 6:03:51 PM
Just make sure the transformer or the input voltage gives at least 5A or else you won't get 5A out of the LM338. However, I am wondering if I can use a general comparator (LM339) instead of the LM301, it seems to work better when simulated in Multisim. -Nick
George
Charge a device of 23V battery from a 24V car battery
Thursday, March 05, 2009 6:45:13 AM
I was wondering if I can charge a 24V lead acid battery from another 24V lead acid battery. Can I remove the charge from one battery and transfer it to the other? If yes, which electrical device could do this? Thank you
Dark
Car Battery Charger
Monday, February 16, 2009 12:01:59 PM
Can I replace the LM350 with an LM338T? To get 5A current
alberto
Car Battery Charger
Thursday, January 29, 2009 11:16:57 AM
Hello, I have to charge a lead/acid battery 6V 140Ah (!!), will this circuit functioning? Which part should be modified? Thank you
oscar
Car Battery Charger
Friday, January 09, 2009 5:16:31 PM
good diagram.
ray fok
Car Battery Charger
Wednesday, December 24, 2008 11:53:48 AM
I have a 20-year old car battery charger (12 volts) still in good condition. My question is : can I still use it to charge a late model car battery ?
Chuar
Car Battery Charger
Wednesday, December 17, 2008 11:19:23 AM
Sorry for disturbing, if i'm using solar panel(17-20V,3Amax), replace the 18Vin in ur schematic diagram, and charging the distilled water car battery(12V33Ah), will this circuit functioning? or which part should be modified?
mark leow
Slow Car Battery Charger
Saturday, November 29, 2008 5:10:42 AM
I need a car batteries charger when I'm away say .... about one month. All I need is to connect to my garage electricity supply and the other end to my car battery. This 'Slow" charge will able to maintain the battery power , hence to preserve the electronics memory. Is there such a charger available in the market now?
gee
Car Battery Charger
Tuesday, October 28, 2008 2:51:15 AM
In the schematic of the circuit says it needs 18 v input and the output of the transformer of the power supply circuit is just 15v. That means output of the power supply circuit is less than the input of the charger circuit (18v). Is that ok ?
OZAN SEVİNÇ
Car Battery Charger
Saturday, October 18, 2008 4:57:39 AM
hi anonymous. in this circuit, I could'nt find D1 1N457 Diode. What can use the another one?
anonymous
Car Battery Charger
Thursday, September 25, 2008 10:12:07 AM
what is the maximum input current that can be handled by the LM350 regulator? also, my input voltage fluctuates between 9v and 20v (pedal DC generator) and I would like to add a smoothing capacitor, what size cap do you recommend?
anonymous
Car Battery Charger
Tuesday, September 16, 2008 3:01:22 AM
does anyone know what the circuit in the above schematic outputs? is there any modification required inorder to get 2A and 15v at the output?
anonymous
Car Battery Charger
Tuesday, August 12, 2008 11:56:44 PM
what is the output voltage in the circuit
laura
Car Battery Charger
Saturday, August 09, 2008 9:52:34 PM
this am i charged my boat battery. then tried to start the boat it wouldnt start. so went to make sure battery had full charge, since i ran it down trying to start it. well now the light on my battery charger is lit when i firsyt plug it in. i havent even attached the black and red leads to the battery. but when i do attach them both the green charge lite goes out. but if i disconnect 1 of the leads the light comes back on. it didnt do that earlier this am when i first charged the battery. i know its in the charger. but how do i fix it? is a fuse blown in the charger/ pleas ehelp if ya can thanks L
Rockets
Car Battery Charger
Tuesday, August 05, 2008 3:56:35 AM
Hello, can you explain how the circuit works? and what is the circuit supply? is it AC or DC?
anonymous
Car Battery Charger
Friday, August 01, 2008 4:29:08 PM
Can this circuit be used to charge small SLA type batteries(4.5AH)for example?...Id hate to have one explode in my face..it would really ruin my day;)
blaise
Car Battery Charger
Friday, August 01, 2008 9:30:35 AM
is s1, of the charger section, a momentary switch ? or fully latched.
RODNEY LAMAY
Car Battery Charger
Thursday, July 31, 2008 9:11:46 PM
Sir I have a 18 volt output solar cell All markings are off,I checked the output with my Multi Meter.What ma or watts will it put out please with your curcuit as shown. Does it turn itself on and off ? why does it need a switch ? Will it work without one ? Thank You Rodney LaMay
anonymous
Car Battery Charger
Thursday, July 31, 2008 5:45:09 PM
Can i charge 12V battery with 24v charger?
anwendyburton@onwywendymous
Car Battery Charger
Saturday, July 05, 2008 4:35:17 PM
hi please can you advice I have a 6 amp charger,I have put a lesiure battry on, so I can use in my caravan, the light was green when I put the charger on today the full charge light is red. Does this mean the battery is fully charged or dead .
anonymous
Car Battery Charger
Sunday, June 22, 2008 8:57:33 PM
Looked at the comments, many seem new or are confused. This charger will charge at 3 Amps Max. (with heatsink on Regulator) The circuit works by monitoring the current through the voltage drop through the series output R7 (the more current, the lower the voltage). The op-amp (as a comparator) compares the output with the reference voltage provided by the R4/R5 Voltage divider. When "on", the output of the op-amp is high, no current flows through Q1 or R6. When the charging current drops (batteries draw less current from charger the closer they are to 'full'), the voltage drop across R7 decreases, increasing the voltage at the inverting input of the op amp. When that voltage is higher than the reference from the R4/R5 voltage divider, the ouput of the op-amp goes low, putting R6 in parallel with R2, and turning on Q1 which turns on the LED. R6 in parallel with R2 lowers the voltage on the adjust pin of the regulator, effectively turning it off. The circuit allows a 30mA trickle charge through R1, which also provides power to the circuit. My opnion is that a 3 Amp charger IS a trickle charger, There are lots of other circuits around that use several paralell MOSFETs to get high/normal charge rates. 2 amps on a half-dead battery would take over a day to charge. However, the low current method is the only way to salvage a fully discharged lead acid battery, if at all. Hope that answers everybody's questions. (no, I didn't create this circuit, just came across it and thought I'd comment)
Mike
Car Battery Charger
Monday, June 16, 2008 11:50:21 AM
Ok Azam, Trickle type chargers apply low current to batteries, there is some debate over whether or not this is harmful but most decent chargers shut off when the battery is full. If you are simply going by the packaging you want a charger labeled as "intelligent." It contains a microprocessor that monitors the state of charge and when it is done charging, checks the voltage every hour or so just to see if the battery is still fully charged. What you definitely do not want is an old-fashioned 'trickle-only' charger, I don't even think anyone sells them anymore, they are just a power supply and a diode, nothing else.
henry
Car Battery Charger
Friday, June 13, 2008 9:10:16 PM
what is the substitute for the IC LM 301,can LM 317 be use instead of the LM 350
Georges
Car Battery Charger
Friday, June 06, 2008 3:49:48 AM
First when i connect the circuit to power or to the batterie the led turned on . Second if the circuit is connected to power and i connect the batterie the lm301 suddenly corrupted. third the open switch when pushed the led turn off. the batterie used is lead acid batterie 12 volt 7A the power supply 20 volt DC created from a transformer 24v 3A with a bridge 5A. Please waiting your feedback.
faisal billah
Car Battery Charger
Sunday, June 01, 2008 11:55:17 AM
wonderfull idea,very usefull
Azam
Car Battery Charger
Friday, May 30, 2008 6:49:08 AM
Can someone compare and explain why battery chargers in the market have trickle charging system that takes twice the time to charge a car battery.How can I tell if a charger is trickle type. I need fast charging that I believe is available only in Full wave bridge charger.Please educate me
Mike S
Car Battery Charger - what's the switch for?
Saturday, May 10, 2008 7:01:53 AM
Hi, I was wondering if anyone's built this ct. and had it working 100% correctly - following the schematic exactly. Also, what's the switch for? It looks like it temporarily stops charging but I'm not sure about that. And why doesn't the author reply to any of the questions that have been asked here? Thanks, Mike
anonymous
Car Battery Charger
Monday, May 05, 2008 8:16:54 PM
can anybody please explain how the circuit works? i'm a beginner in electronics
naleli macclay
Ni-Cd checker
Friday, April 25, 2008 8:36:53 AM
its my first time, to visit this site so i guess am impressed.
anonymous
Car Battery Charger
Monday, April 21, 2008 12:45:37 PM
This circuit is "old" and right out of National Semiconductors LM138 "Typical Applications". It works well... ~20 years ago I built a 40A version... and it's still running today.
Tom
Car Battery Charger
Friday, April 18, 2008 12:04:35 PM
Hey, I am looking to build a battery charger, but my application is for a battery powered welder. So I will be pulling approximately 100 amps off of the batteries. Will it hurt this charger to be connected when drawing 100 amps off the batteries? If so, is there a clever way to make the battery charger disconnect when the battery amperage is high? Thanks
Ilya
Car Battery Charger
Tuesday, April 15, 2008 3:26:31 PM
What changes should be made to the circuit in order to use it for a 12V battery. Also, the battery I am planning to use is a higher current battery than an average car battery. Should I consider making any changes to the circuit? Thank you.
anonymous
Car Battery Charger
Friday, April 04, 2008 7:01:58 PM
jotham - "quote from the author" "When the battery is fully charged, the circuit switches off and lights a LED, telling you that the cycle has finished." vicky - id check the transistor Q1, it has to be PNP and properly connected so the led works properly, also check the ouput of the OP amp, it should be connected to the base of Q1, maybe thats it... Anonymous (Feb 19) - well duh , go to walmart or something, this site isnt meant for that Anonymous (Feb 8) - (N1/N2) = (V1/V2) so the turn ratio should be directly proportional to the given voltages, but considering current calculations (wich i dont have at hand now) getting the laminated nucleus, etc... you are better off buying one than making one, they are usually sold in voltage and current rating, like " a 120 VAC to XXVAC XAmps transformer" Anonymous Feb01 - it is most likely to work, i mean... voltage isnt much of an issue as long as its higher than 14 volts or so, however as you can see in the power supply he suggests a 5A bridge rectifier, if the circuit draws that much current and your solar panel doesnt handle at least that much current things might not work out, id like to know the maximum current the circuit draws
Olebak
Car Battery Charger
Friday, April 04, 2008 4:50:02 PM
I'm a bit confused about this charger . 1 the LED is always on when power is applied to the circuit, 2 how does this comparator operate and what is it comparing. could you please elaborate a bit more on how the circuit operates please. Any one who can help please do.
Chris Dreyer
Car Battery Charger
Sunday, March 23, 2008 5:19:17 AM
HI, THANK YOU FOR A VERY USEFUL ARTICAL. SOMEWHAT A NOVICE WITH CERTAIN ASPECTS OF ELECTRONICS AND CHARGERS, I NEED TO ASKED A QUESTION OR TWO. IN SOUTH AFRICA WE EXPERINCE A LOT OF POWER FAILURES AND HAVE TO FIND ALTERNATIVES TO ATTEND TO THE ESSENTIALS, LIKE MY MOTHER BEEN ON OXGESION. 1. CAN THIS CHARGER CHARGES TWO BATTERIES SIMILTANEOUSLY? (TWO 12 V BATERIES IN PARALLEL) 2. WHAT ARE THE MAXIUM O/P CURRENT THE CHARGER GIVEN THE FACT I WANT TO CHARGE TWO BATTERIES SIMILTAIONSLY. YOUR FEEDBACK WILL BE APPRECIATED. REGARDS CHRIS
santhosh
Car Battery Charger
Wednesday, March 12, 2008 10:17:03 AM
I have a battery but i don't know the Ah of the battery.It is a motorcycle battery.can i charge it with this circuit.What will be cost of this project?
princy
Car Battery Charger
Saturday, March 01, 2008 12:55:31 AM
Is there any possibility to make the car battery charger work whit using heatsink?
jotham
automatic Car Battery Charger
Friday, February 29, 2008 3:59:10 AM
hi .if the battery is full of charge what is the reaction of this charger.?
vicky
Battery Charger
Thursday, February 21, 2008 3:24:47 AM
I've tried wiring the circuit but the LED is permanently on, what can be the problem? Also how does it regulate such that when the battery is full, it won't overcharge? Also the connection for lm301 is not clear, where is pin 5 connected and pin4 is not clear. Can is use lm741 if i don't have lm301?
anonymous
Car Battery Charger
Tuesday, February 19, 2008 6:01:05 PM
This site helped me none on finding out what type of car battery charger I should purchace.
ugo
Car Battery Charger
Tuesday, February 12, 2008 8:14:59 AM
can u send me a circuit diagram of a 12V automatic battery charger

(Editor's notes: Just look at the "Related Circuits" section of this page.)

anonymous
Car Battery Charger
Friday, February 08, 2008 6:59:13 AM
how do one calculate turns ratio given only primary and secondary voltage
anonymous
Car Battery Charger
Friday, February 01, 2008 5:03:29 PM
If i would use a lower voltage than 18v, would this stop working then. I'm only asking this because i would like to connect this to my solar panel which is able to deliver me 17.2 V. I'm willing to use this in my RC solar powered car
anonymous
Car Battery Charger
Friday, December 14, 2007 2:47:15 AM
i just would like to say, that the opamp is a comparator in this case inorder to tell that the battery is full and the PNP is used inorder to invert the output of the opamp, NPN can be used preceded by inverter but it will be pointless. I designed a charger using burt tech. but i'm not pretty sure about it. it uses a Pic processor.if some1 interesting send me a mail.
?????
Car Battery Charger
Thursday, December 13, 2007 2:22:44 PM
omg this wesite is really help full!!!!!
marki
Car Battery Charger
Wednesday, December 12, 2007 11:52:07 AM
HI MISTER. WITH THIS CHARGER I LIKE TO CHARGE 160Ah BATTERY. ITS POSSIBLE OR NOT .PLEASE TELL ME THANK YOU IN ADVANCE
anonymous
Car Battery Charger
Sunday, December 09, 2007 8:26:58 PM
I need to charge a 125 VDC battery bank, do you have any schematics of a battery bank charger what help us in our project?
Saad
Car Battery Charger
Monday, December 03, 2007 1:16:54 PM
HI. ME DOING ELECT. ENGR. HOW MUCH TIME REQUIRED TO CHARGE 65 APMARE BATTERY TO FULLY CHARGED????
anonymous
Car Battery Charger
Wednesday, November 28, 2007 1:47:45 PM
I have a 24V transformer, would it hurt anything if I use it in this circuit.
ertur
Car Battery Charger
Friday, November 16, 2007 10:57:52 AM
Hi I am a final year mech engineering student doing my final year project which involves the building of a wind turbine. I need to charge up batteries from a dc generator by means of a trickle charger and voltage regulator. Do you have any schematics that i could use to perform this operation Your help would be greatly appreciated ertur
ertur
Car Battery Charger
Friday, November 16, 2007 10:53:03 AM
can you analyse the Car Battery Charger circuit by details please :)
hussain al lawati
Car Battery Charger
Sunday, November 11, 2007 1:09:35 AM
What is the purpose of using a pnp BJT and the OP-Amp? Can we use an NPN transistor? Why or why not?
Sherihan
Car Battery Charger
Saturday, November 10, 2007 6:06:03 AM
can you analyse the Car Battery Charger circuit by details ?
Ranjan
Car Battery Charger
Friday, November 09, 2007 4:06:59 AM
How can I make this circuit to charge 24 volts battery?
anonymous
Car Battery Charger
Thursday, November 08, 2007 9:41:06 AM
where is the point for the power supple of this circuit above
anonymous
Car Battery Charger
Friday, November 02, 2007 3:13:16 AM
Could you explain to us the slow charge and fast charge charger in a sealed lead acid battery? Thanks!!!
Uberfly
Car Battery Charger
Thursday, November 01, 2007 2:30:59 PM
Fantastic! I've been looking for a simple working circuit like this! Thanks a lot...
Jimmy
Car Battery Charger
Wednesday, October 31, 2007 10:47:56 AM
The diode in series with R3 is LED.
Jimmy
Car Battery Charger
Wednesday, October 31, 2007 10:30:18 AM
What is the description of the "diode" in series with R3.
Andrew
Car Battery Charger
Saturday, October 27, 2007 10:37:10 AM
pls how would i upgrade this battery charger to deliver 15amps
anonymous EMMANUEL SEGUN ALABI
Battery Charger
Friday, October 19, 2007 6:56:35 AM
sir,i am a student of mechanical engineering at university of Ilorin,Nigeria.if a battery charger got burnt in the process of using it by producing smokes,what are the likely causes and solution to this problem. I wish to design battery charger and electrical inverter,kindly suply me with the descriptions and circuit diagrams on how to go about it.Thanks in anticipation.
vaibhav vijay rane
solar-wind charger.
Tuesday, October 16, 2007 4:53:01 AM
sir, We the students of final year Mechanical engineering are making a charger which will consume both solar & wind, the two non-conventional energies at the same time through a generator, via.I.C(integrated circuit) to a storage battrey from which it can be used whenever needed.This charger can be used to charge many electronics equipments(example: lap top, mobiles,i-pods,etc) so we request u to please give us as many information that u have with u. waiting for u'r reply........... thanking you in anticipation
Tori
Car Battery Charger
Sunday, October 07, 2007 10:01:09 AM
Would you be able to supply me with a brief description of how this circuit works?
anonymous
Car Battery Charger
Friday, September 21, 2007 9:49:17 PM
Is it possible to charge a 9V Battery with a battery charger with alligator clips???
chigozie
Car Battery Charger
Monday, September 17, 2007 7:25:27 AM
pls after building this circuit can it work ? besides, i would like to be visiting this site regularly what can i do?
Novi
Car Battery Charger
Monday, September 17, 2007 4:45:15 AM
hi, I try to buy 0.2 Ohm 10 W Resistor & 1N457 Diode, could U give me another alternative for these two component ? thank's a lot
anup
Battery Charger
Thursday, September 13, 2007 2:48:03 AM
i wanted to know about a circuit for a battery charger where even if the input voltage keeps varying, it should not affect the battery charging procedure. i wished to install such an arrangement in vehicles where the speed keeps varying & i do not want the voltage input to affect output voltage. thank you.
kisskisng
Car Battery Charger
Wednesday, September 05, 2007 11:16:47 AM
hi i want ask you about your Car Battery Charger if the battery is empty can i use it or not plz i need your answer
yogesh
Car Battery Charger
Monday, August 27, 2007 11:06:41 AM
hey i m also doing a similar sort of project on battery charging using wind energy any ideas how to go about wind turbine
anonymous
Car Battery Charger
Friday, August 24, 2007 9:26:10 AM
pls, i'm in need of the car battry charger cct analysis. God bless you for responding positively. Thanks, Egbirika J.N.
rainer
Car Battery Charger
Friday, August 17, 2007 5:43:56 AM
i need to charge a 120 volt dc battery bank with 10 amp can any one help rainer
Odel
Car Battery Charger
Friday, August 17, 2007 4:05:13 AM
Can I ask you a favor to provide me a manual charger using my bicycle. I am in a remote area using a battery for my flourecent lamp. I used to bring back my battery to nearby town for charging. I will greatly appreciate if you can help me with my problem. Thank you very much in advance.
anonymous
Car Battery Charger
Tuesday, August 07, 2007 2:04:28 AM
this circuit is a copy from national semiconductors LM 338 voltage regulator Ic data sheet. better we search LM338+pdf in google.
NALEN
Car Battery Charger
Monday, August 06, 2007 10:37:49 AM
Hi Im a currently a final year mechanical engineering student doing my final year project which involves the building of a wind turbine. I need to charge up batteries from a dc generator by means of a trickle charger and voltage regulator. Do you have any schematics that i could use to perform this operation Your help would be greatly appreciated Nalen
rahman ajani
Car Battery Charger
Thursday, August 02, 2007 1:09:08 PM
pls, i need to know if i can get a circuit on automatic 12v battery charger.using 2 ics and 2 transistor.pls i need ur help its my school project
wilham
Battery Charger for microhydro
Friday, July 27, 2007 1:25:04 AM
hi, i'm from indonesia, i need u,r help to make a battery charger with constant voltage but in different current and this battery connected to inverter and synchronized to system microhydro... thanks a lot
Collins
Car Battery Charger
Tuesday, July 24, 2007 8:21:16 AM
Please, How can I use this Charger on a 120A Dry Cell Battery? Need full schematic diagram and modifications.
James
Car Battery Charger
Sunday, July 22, 2007 3:52:31 AM
Brilliant. one press and away it goes. everyone is asking stupid questions...... Why would you want to use it to run an inverter (12v to 120v) If you were using this charger off 120v you wont need to. and if you were using a battery to charge a battery (Dumb) you would just connect the inverter to the battery---FORGET THE CHARGER
saheed
My question is
Friday, July 20, 2007 11:08:13 PM
The Ampere-Hour-Rating of the battery charger, and also how to calculate the rating of the power.Its a nice project and i will like to used it as my own project.Can u pls send me the solution to my question.
Waleed
Car Battery Charger
Tuesday, July 17, 2007 4:09:52 AM
hey ; can i use this circuit to charge 6 V motorcycle battery ? and thanks for help :)
Mohamed
there is a question
Saturday, July 14, 2007 8:06:43 AM
can i use this circuit to charge a 6v battery used in motorcycles? and thanks for your help please if my question has any answer, send this answer for me
andrey
Car Battery Charger
Saturday, July 14, 2007 4:18:55 AM
can this circuit to charge the AA NiCd/NiMh,and how to make this circuit has a display to know if the battery has been full..please give me answer

(Editor's notes: No.)

Qazi Muhammad Imran
Car Battery Charger
Friday, July 13, 2007 8:36:25 PM
This circuit isvery halpfull...
john raul cormina
Car Battery Charger
Wednesday, July 11, 2007 7:48:51 PM
is this circuit can charge a 12 flets car battery?
anonymous
Car Battery Charger
Tuesday, July 10, 2007 12:46:14 AM
how should a pair of underage naive teenagers go about charging a car battery with no experience without a second car BUT we do on the other hand, have access to a car battery charger?
bright
Car Battery Charger
Saturday, July 07, 2007 4:12:20 PM
please can i use this charger for 12V TO 120V INVERTER,i will not use it in a car
anonymous
Car Battery Charger
Tuesday, July 03, 2007 10:47:19 PM
How can it be upgraded to be able to charge a 200AH battery?
adewale raji
Car Battery Charger
Wednesday, June 27, 2007 8:21:45 AM
can l get one for 62Ah
Benny
Car Battery Charger
Sunday, June 24, 2007 6:27:28 AM
Is the power supply needed 18 V and no less? Could AC/DC adaptors also be used as power supply? Can you provide substitute parts description as alternative in case we don't those listed in our country, Philippines? Is there a way to detect the actual charge in volts? Is there a time limit for this to charge?
anonymous
Car Battery Charger
Friday, June 22, 2007 7:15:32 PM
can i use 1A transformer (15v)
mohamed
Car Battery Charger
Monday, June 18, 2007 7:34:09 AM
can i use solar panel as a power supply
anonymous
Car Battery Charger
Friday, June 15, 2007 10:07:17 AM
Nice work, its a good circuit, this charger is good when the battery of the car is uncharged.
jafoy
Car Battery Charger
Friday, June 15, 2007 2:58:13 AM
kindly,give some substitutions in 1n 457 diode.because the availability of this product is scarce in ph. also include the pcb layout in this project. i have replaced 1n 457 with 1n 754(6v) but the charger is subjected to glitch!!!!! a need ur immediate response... thank u....
Tommy
Car Battery Charger
Thursday, June 14, 2007 8:17:43 AM
May you provide this battery charger for 255 amps? Thank you very much
thandoswaziland@yahoo.com
Car Battery Charger
Wednesday, June 13, 2007 7:54:57 AM
can some please explain what is go on because it is ideal as a project
thando
Car Battery Charger
Wednesday, June 13, 2007 7:22:56 AM
how does this circuit work, as in step by step analysis, from the heatsink down to the battery terminals
anonymous
Car Battery Charger
Tuesday, June 12, 2007 6:04:02 PM
That is a simple circuit, and should work on most batteries of 100 Amp hour or less. Could use the Op Amp to drive a opto scr driver circuit for more amperage. Would need a larger transformer though and scr's.
Roy Laybutt
Car Battery Charger
Friday, June 08, 2007 8:06:01 AM
Can you provide this battery charger for 120 amps please Roy
anthony akabueze
Car Battery Charger
Wednesday, June 06, 2007 8:57:28 PM
it's wonderful.keep it up!
ack Hunter
Car Battery Charger 2/4/6 amp car battery charger
Wednesday, June 06, 2007 1:36:40 PM
What does the 2/4.6 amp mean?
Philip E Lori
12 volts Car Battery Charger
Friday, June 01, 2007 6:38:21 AM
I want to know the principle of operation i.e how it works, the minimumand maximum amount of current required. I also need the design calculation of the circuit.Please i need it as fast as possible.
SEYI
Car Battery Charger
Thursday, May 31, 2007 5:36:29 AM
i want somebody that can put me thru cos i'm using it for my project
Terry
Car Battery Charger
Tuesday, May 29, 2007 2:15:12 AM
Hi, Does anyone have a PCB layout for the battery charger? It would be much appreciated! Cheers
anonymous
Car Battery Charger
Monday, May 21, 2007 2:52:27 PM
the circuit could be very usefull if i could connect it with a small dc generator (from wind power), but 18V on the board suplly is dc or ac?
anonymous
Car Battery Charger
Friday, May 18, 2007 8:34:06 PM
Tested it using a TLO81 instead of LM301A, work perfecly.
gm_karutz
Car Battery Charger
Sunday, May 06, 2007 8:00:00 AM
Is this can be use in dry cell battery?......can i use larger amperage for this project?
R.V.Raghav
Car Battery Charger
Thursday, May 03, 2007 12:46:44 PM
can it be used to charge a 12V UPS storage battery of 1.5A(approx.) otr a motor cycle batt. of 12VDC and what if i connect it to a solar cell of 17.8 (0.4x4x11 = 17.6VDC?)
anonymous
Car Battery Charger
Thursday, April 26, 2007 12:16:24 PM
I am looking for a transfomer with a rectifier (Charger) which deliver a continuous load to a 12-volt Motor with a permanent magnet continuous runing. There is such a thing? Thanks J.U.
louis
Car Battery Charger
Monday, April 23, 2007 1:58:36 PM
How do i change this clever circuit from 12v to 36v charger .thank you ....
ramy
Car Battery Charger
Sunday, April 22, 2007 12:23:40 PM
Hi Could we use this charger for dry dattery? THank you
Dina
Car Battery Charger
Wednesday, April 18, 2007 1:01:59 PM
This circuit is very useful ,I want it in my graduation project but I want more details about the operation of this circuit,as for first more information about regulator U1 also information about the input of the circuit ,please answer me in fast time,thanks.
janb maicheal alga
Car Battery Charger
Wednesday, April 04, 2007 12:56:50 PM
could i connect two or more batteries connected in parallel?or if not, ill use a 15A transformer in order to make current enough for the batteries. could you send me how this circuit work?that wen i press the S1 the op amp will balance an compensate the voltage supply to the battery, how it detects the current of the battery and how it switches off the systym.I just wonder how it switches off b'coz i examine the connection its just a parallel connection and directly connected to battery....hope for your response.
Clint Wood
Car Battery Charger
Friday, March 30, 2007 2:02:18 PM
Will this work for a solar panel as the power supply and is it safe for a deep cycle battery. e.g. sailboat battery
alex
Car Battery Charger
Friday, March 30, 2007 11:09:26 AM
the LED in instantly on, and when i press the start button it shuts off,while it is pressed. Any ideas why
scotty243
Car Battery Charger
Monday, March 26, 2007 12:07:47 PM
Pins 1 and 6 are NOT shorted together, and pin 5 is not connected to anything.
Catharine McCasland
Car Battery Charger
Monday, March 26, 2007 2:58:56 AM
Will this item charge a toyota 4 wd 6 cyclinder sux
ruko
Car Battery Charger
Saturday, March 24, 2007 9:10:39 PM
Have you posted the answers to the above questions somewhere?

(Editor's notes: As it noted before the comments section, technical questions in comments are generally NOT answered by the webmaster. Your best bet is to search the forum.)

Ben
Car Battery Charger
Tuesday, March 20, 2007 4:06:51 PM
The connections for U2 are not completely clear. Are pins 1 and 6 shorted? What is pin 5 connected to?
J Stanley
Car Battery Charger
Monday, March 19, 2007 4:51:03 AM
Can this be used to charge a 6volt motorcycle battery and wich components will to change
anonymous
Car Battery Charger
Monday, March 19, 2007 1:43:50 AM
please include foil layouts and pcv
Rampa
Car Battery Charger
Saturday, March 17, 2007 8:05:18 PM
Hi guys. im from Argentine... and i got a question. Why only i got 4v 3.3A in the output???? that is normal?? anyway later i go try charging a baterry. bye bye. and sorry my english sux.
anonymous
Car Battery Charger
Friday, March 16, 2007 5:00:35 PM
When connecting the charger to the battery, do you connect positive to positive or positive to negative?

(Editor's notes: What do you think? + to +, - to -)

kva
Car Battery Charger
Thursday, March 15, 2007 4:08:39 AM
Can i install it on car with the input replaced by curren generator ?
anonDave Morrisymous
Car Battery Charger
Saturday, March 10, 2007 8:16:29 AM
I have just completed the build and test of this circuit (which I have seen in a 1979 National Semiconductor handbook by the way!) and the charged voltage and current rates seem to work. The LED remains permanently illuminated, however.
Kalesh
Car Battery Charger
Wednesday, March 07, 2007 11:36:12 AM
what is the rating of the regulator? is it normal three terminal device or special high wattage one?how can I adjust the cut off voltage of the charger when battery is fully charged?
funsho adigun and co
Car Battery Charger
Wednesday, February 28, 2007 11:41:48 AM
how will i be sure that this circuit will work effectively
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